This is a question me and my brother wonder about sometimes. What will happen, eventually, to REALLY major franchises, like Mario, Zelda, GTA, etc; ones that can continue to spawn ''sequels'' without having to carry on any cohesive, continuos storylines.

Will, for example, our grandchildren be playing the new Mario games? Or will they die out completely, except for fan made tributes. And if they do die out, what would cause this/lead to this breaking point?

Not really a topic with a clear answer, but I'd just be interested to hear some other people's thoughts on this. 

i think Mario and all that stuff will continue forever, as will Final Fantasy. GTA will end eventually, but not for a while. The largest franchise that I think will end soon is Ratchet and Clank, I can't see any more games after the next one

Some will die this generation while others will live on. Same as always. I think almost all the mega-franchises (especially the Nintendo ones) will live on. I can't say I like the derivativeness of franchises, especially once they reach the fourth installment, but people like a name they recognize. Same reason Hollywood blockbusters do so well.

At least some of them, like the Mario franchise, are still very innovative. GTA 4 doesn't look half bad either, and I talked mad crap about San Andreas.